Method for treating heavy vegetable oils



H. s. ADAMS ETAL METHOD FOR TREATING HEAVY VEGETA-BLE OILS `Tan. l, '1929.

Filed Jan. 13, 1926 Lun (w16 Patented J 1, 1929.l

L'J'Nlran STATES PATENT carica.

HAROLD S. ADAMS, OF NEW ROCHELLE, YORK, AND LUDWIG MEUSER, OF BOUND- NAU TUCK, CONNECTICUT, A CORPORATION OF CONNECTICUT.

METHOD FOR TREATING HEAVY VEGETABLE OILS.

- Application filed January 13, 1926. Serial No. 81,089.

This invention Vrelates to a method for treating heavy vegetable oils, more particularly to a method for cracking castor oil to obtain heptaldehyde. y f Until comparatively recently the-1najor ity of the heavier aldehydes were mere laboratory Curiosities, but-in more recent years they have become of considerable com- \mercial importance, for instance in making 'vulcanlzation accelerators by forming con- -heat castor oil in bulk in a glass vessel, in

vacuum or at atmospheric pressure, to a tem eratureof 450 to 500 C., the castor ein thereby cracked 'and producing heptalde yde among the decomposition v products. This method of preparing heptaldehyde is wasteful by reason of the relatively small yield, is more or less dangerous, and is open to numerous other objections.

W'hen the .castor oil is rapidly heated itv tends to foam and at the Sametime by reason of polymerization the liquid becomes rendered spon'gy or lporous b very viscid-and soon sets to a gel whichis the decomposition gases which are distri u ted through it. It is impossible to maintain thetemperature of the body of this gel to the reuired degree to crack it since its porous orm renders it a very poor-conductor of heat, and by reason of the large increase in volume' the receptacle is liable to 'be burst orv the outlet to the condenser blockedor both. .f i

Anob'ject'of A improved method for cracking heavy vege- A table oils such as castor oil.

Another ob]ect is to provlde an improved method for obtaining heptaldehyde from castor oil. y Y l Other objectswill appear from the detailed descriptions and claims.

'.Without intention to limit the invention" other than as required by the-prior art, it

'our invention is .toprovide an pipe 1 and part elevation of a sultable apparatus.

The apparatus for cracking the oil will iirst be described, and in this apparatus the numeral 1 represents a furnace supported upon llegs 2, the outer casing of the furnace being formed of any'suitable heat insulating material such as silocel brick 3. Within the s ilocel brick is a lining 4 of fire brick formlng a heating -chamber 5, and in this chamber is disposed an electric heating ele- A ment 6. However, the furnace maybe heated in any other4 desired manner. Passing through the heating chamber 5 is a passage-- way or chamber for the oil to `be cracked,

which passageway in the'present instance is formed of an inclined nichrome pipe. However, any other suitable material which is inert -to the decomposition products may be employed, such as duriron or silica.' At the upper or inlet end of the pipe 7 a fitting 8 is connected in \'which is disposed an' S pipe 9 to form a liquid seal, while to the outer end of this pipe a sight feed cup l0 is connected. A graduated supply of' the NEW JERSEY, ASSIGNORS T0 THE NAUGATUCK CHEMICAL COMPANY, 0F

oil to be cracked is supplied to the cup 10 by the valve controlled pipe 11, leading xfrom a tank 12. The lower end of pipe 7 is connected to an over flow pipe 13 extending lintoa sump 14 and opening into the latter adjacent to the'bottom, Aso as to main'- tain a liquid seal. A second overflow 4pipe 15 extends from thenpper portion of the sump 14 and delivers into a receptacle `16. Leadin from the connection 8 is an exhaust for the decomposition products, which pipe is connectedlto a condenser 18,

and the` latter deliversfthe' condensate throughy a pipe 19 into 'a receiver 20. At-

taehe'd to. the .lid-of therecever 20 is an excastoroil is supplied to the pipe in a small stream so regulated that it is continuously and completely decomposed and the decomposition products volatilized without "any residue of undecomposed or partly decomposed oil. If by reason of improper regulation there should be a residue of oil, the same flows throughthe pipe 13 and into the sump 14 to form a liquid' seal for the appa-.

ratus, However, under proper operating )conditions there should be no residue and The products `oft if so the seal may' be otherwise provided.

bons, fixed ases, and a relatively large proportion of eptaldehyde mixed to some extent with other aldehydes and ketones. The

decomposition products pass .through pipe 17 to the condenser 18 and arecollected in the receptacle 20, while the ixed gases are' exhausted through pipe 21. The condensate is then steam distilled, and in this operation the .ndecylenic acid, being non-volatile in steam, is left behind in the still. The acrolein has a relatively low boiling point (52.4

C.) and'is appreciably soluble in water, while the heptaldehyde has a much higher boiling point (153.5 C.)'and Ais insoluble in water. Hencel by maintaining the condensery of the 4still at a Vrelatively lo'w temperature,l for instance to 7.50 C., the heptaldehyde is Q condensed Vandthe acrolein either dissolves in water present or passes ofi' as vapor. The

crude heptaldehyde product thus recovered is a pale yellow, water-insoluble liquid which consists essentially of he taldehyde.

'The yield 4of -crude heptaldehy eis about 25% by Weight of the 'castor oil, and this prcduct analyzes about pure heptaldey e. 4 It is desirable thatthe tube 7 be formed ,oa material which is inert to the'decomposition products, since if some other material y' such as cast iron be used it has been found that the yield' of heptaldehyde'i'sconsiderably reduced. Steel or' wrought iron tubes may be used, but require exact temperature' conditions 'to' obtain a satisfactory yield, and are therefore more critical to operate than one formed of non-Catal tic material. .The best temperature for the ecomposition is at about 450 to 500 C.',`and asbefore stated. by properly balancing the temperature and the 'rate of supply ofthe castor oil thelatter will be completely decomposed y decomposition are `-undecylenic acid, acrolein, various hydrocarwithout any overflow. While in the present specific apparatus the castor oil has been permitted to flow in a `s mall stream through a heated inclined pipe, it is obvious that any other apparatus may /be utilized by which the castor oil in attenuated or finely divided for is 1subjected to the proper temperature. By the invention all forniation of gel and consequent useless -residue is avoided as well as risk of explosion, and atl the same time a largely increased yield of heptaldehyde is obtained.

While in the specific example given, thel process has been appliedl to the` cracking of castor oil, it is obvious that the broad,

process is equally -wellapplicable to the cracking of lother heavy vegetable oils, and it is not desired tol limit the invention otherwise than as set forth in theappended claims. 'i v Having thus described our invention what We 'claim and desire to protect by Letters Patent is completely decompose the oil and volatilize` thedecomposition products, said temperature being-below the decomposition temperature of heptaldehyde.

2. The ,method oils which comprises slowly-passing castor oil in attenuated form through y a heated zone in the absence of air or catalyticagents and maintaininga relatively high temperature in said zone suiicient to substantially complletely decompose the oil and volatilizet e decomposition roducts, said temper- 1. VThe .method of treating heavy vegeof treating heavy vegetable i' ature being below the ecomposition tempery ature of heptaldeh dep 3. VThe method o treatin heavy 'vegetable oils. which comprises slow flowing castor oil in a lthin stream throng4 a passage having vwalls of non-catalytic material,` and maintaining a relatively hightemperature in said passage ,-sufiicient to com letely decompose the oil and volatilize tlhe decomosition products,''said temperature being beow the decomposition temperature of heptaldeh de. j

table oils which comprises eating castor oil in attenuated form in Ithe absence of catalytic'agents to a cracking temperature not substantially ing 'a decomposltion product therefrom.,

5. The method of treating heavy ve etable owing oils which comprises continuously over 500 C. and recovercastor oil ina thin stream through a passage of limited cross sectional areacomposed of material inert to h eptaldehyde about 450 'C, externally heated to 500 to 600 C., on- 13o dehyde from the mensa? densing the decomposition products, steam distilling said products to separate heptaldeh de and acrolein from undecylenic aci and. separating heptaldehyde from the acrolein by passing through a condenser ieated above the boiling pointof the acroein.

6. The method of treating heavy vegetable oils which comprises continuously Howling castor oil in a thin stream through a tube of non-catalytic material heatedto 500 to 600 C., to thereby substantially completely decompose the oil and volatilize the decomposition products, condensing the decomposition products, distilling at a temperature below the boiling point at undecylenic acid, thereby separating out the latter, condens ing the distillate inthe presence of water at aI temperature below the boiling point of hepta'ldehyde, and recovering heptaldehyde lfrom the condensate.

7. The method of treating heavy vegetable oils which comprises heatlng castor oil in the absence of catalytic agents in a relatively thinly extended forin to a temperature above 450 C., and recovering heptaldecomposition products.

' 8. The method of treating heavy vegetable oils which comprises continuously supplying vheptaldehyde above 450 castor oil in a relatively thinly extended` form to a non-catalytic cracking zone heated to substantially 450-500" C., and recovering heptaldehyde from -the decomposition products.

9. vThe method of treating heavy vegetable oils which comprises passing castor oil through a non-catalytic cracking zone heated.

in an attenuated form through a chamber material inert `to C., heating the chamber above such temperature, and recovering heptaldehyde from the decomposition products.

Signed at New York, county of New York, and State otNew York, this 31st day of December, 1925. Y

HARLD S. ADAMS. Signed at N ew York, county of New York,

formed of a non-catalytic State of New. York, this 5th day of J anuary, 1926.

' LUDWIG MUSEE. 

